Molecular phylogeny and divergence time of Trachypithecus: with implications for the taxonomy of T. phayrei

The genus Trachypithecus is the most diverse langur taxon, distributed in southwestern China, south and southeastern Asia. In this study, we include 16 recognized Trachypithecus species to reconstruct the phylogeny with particular concern to the taxonomy of the three subspecies of T. phayrei using multiple genes. Our results support a sister-relationship between T. p. phayrei and T. p. shanicus. However, the mitochondrial CYT B gene supported T. p. crepuscula as a distinct species, but the nuclear PRM1 gene suggested a closer relationship between T. p. crepuscula and T. p. phayrei. The incongruence between nuclear and mitochondrial genes suggests that hybridization may have occurred, a fact that would benefit from re-examination using multiple unlinked nuclear genes.